IPv6 Autoconfiguration

Plug & Play Dream or
Security Nightmare
Review of IPv6 Autoconfig
Defined in RFC 2461
All hosts implicitly have an IPv6
Link-Local address for each interface they have
Host ÒI have a NIC, therefore I amÓ
FE08::(EIU-64)
Simple Corollary: therefore, a host without a NIC, is a non-entity

Review of IPv6 Autoconfig
Other network information obtained from the Router(s) on the local network
Host ÒIs there a router in the houseÓ
ICMPv6 Type 133 – Router Solicitation
Router ÒIÕm a router and here are the prefixs you can useÓ optionally Ò, and go talk to the DHCPv6 serverÓ
ICMPv6 Type 134 – Router Advertisement

Review of IPv6 Autoconfig
The host combines the prefix information with a host address portion to form an IPv6 Address
Multiple Types of Host Addresses

IPv6 Address Types
Stateless (EUI-64)
RFC 2462
Privacy Extensions (pseudorandom)
RFC 3041
Stateful (DHCPv6)
RFC 3315

So whatÕs the problem?
Well do you know the devices that says itÕs the router is really suppose to be the router?
If you get multiple answers (which you can) which is the right one?

So whatÕs the problem?
It could be a miss-configured host
LINUX, Widows, or what ever
Maybe with a tunnel that it want to HELP! other people use
More scary, could be a BAD guy claiming to be a router
Trying to setup a man-in-the-middle attack

But IÕm not running IPv6!
Are you sure?
OSes are coming with IPv6 by default
Windows Vista
Mac OSX
Many LINUX
Many other UNIX

But IÕm not running IPv6!
So you probably have hosts asking for an IPv6 router on your network right now
All you need is a missconfigured host or a bad guy on your network and your hosts are doing IPv6

What about SEND?
IPv6 Secure Neighbor Discovery
RFC 3971
It will Secure this, and more!
But!!!!
There are not many, if any, implementations
Certs & PKI
Do I need to say more

What about SEND?
IPv6 Secure Neighbor Discovery
Will work in a well controlled mostly closed network
Not the definition of your typical University Network
Probably not workable on a visitor or guest network even if your primary network is securable in this way

A Solution
Block IPv6 Router Advertisements on ingress to access switch port for hosts
Can be done today with Cisco 3750,
3750-E, 3560, and 3560-E switches
IOS 12.2(25)SED Advanced IP Services (only) or greater code
I tested on 3750s with 12.2(40)SE AdvIPServ

IOS Config Snip
A Different Problem
I said ÒAdvanced IP ServicesÓ
The upgrade from ÒIP BaseÓ is $6,995 list per switch
We have about 3500 – 3750G-24TS
This is about $24M list
WeÕre talking to to the 3750 Business Unit at Cisco

Other Solutions
Turn off IPv6 on your host if your not using it
Not a great solution
Not a solution at all, if you need/want to do IPv6
But can you really insure that you have done this

Other Solutions
Monitor for bogus IPv6 Router Advertisements
Ala XArp type IPv4 ARP monitoring software
IPv6 Routers would be perfect device to do this, track the other router
maybe even do an SMNP trap – maybe not

Talk to you Switch Vendor
We all need to be talking to our Vendors
Talk to them about how you want IPv6 to work 1,2, or 3 years from now
Make IPv6 a requirement in all your purchases
Test the features

IPv6 Support Priority List
for Vendors
Basic Functionality – you can pass IPv6 at all
Security – Comparable security feature to IPv4
IPv6 manageability
Full IPv4 feature parity

IPv6 Access Switch Features
IPv6 Aware Layer2 ACLs
DHCPv6 Snooping
IPv6 Neighbor Discovery Validation
MLD2 Snooping
IPv6 Aware QOS features

Conclusion
Start thinking about IPv6 as part of your normal network
Think about it in the same ways as IPv4
However, take the opportunity to rethink how you are doing your normal networking
Talk to your Vendors early and often